Cardiac autonomic functions are altered in patients with acute leukemia, assessed by heart rate variability

Acute leukemia is one of the leading malignancies worldwide. Although neuropathy was reported as one of the complications of leukemia, there is a little data about the autonomic involvement. This study was designed to investigate the cardiac autonomic disturbances in acute leukemias by using time-domain indices of heart rate variability (HRV). Newly diagnosed 36 patients with acute leukemia (14 acute lymphoblastic leukemia and 22 acute myeloblastic leukemia) and gender- and age-matched 32 healthy subjects as controls were enrolled in this study. The diagnosis of leukemia was established by whole blood count, peripheral smears and bone marrow aspirations. In order to rule out the effect of any medication on HRV, the patients were selected from those who had not received any antineoplastic agent yet. For assessing the cardiac autonomic functions, HRV obtained from 24-hr Holter monitor recordings was used. The age, gender and serum ferritin levels were similar, while hemoglobin levels were lower in the leukemia group. The comparison of the leukemia group and control group revealed that HRV decreased in patients with acute leukemia, which reflects sympathetic dominance in acute leukemia. This is the first study that shows altered cardiac autonomic functions in patients with acute leukemias who are not on any therapeutical intervention. The altered cardiac autonomic functions may be a sign of paraneoplastic neuropathy in patients with acute leukemia.